1. Field of the Invention
This invention relates to a composition which can be added to used metal working fluids to remove obnoxious sulfurous odors as well as to recondition the fluid.
2. Description of the Prior Art
Metal working fluids usually contain an emulsifier which is commonly of a sulfonate type as well as containing sulfur impurities in the oil-base portion of the fluid. These materials act as nutrients for anaerobic microorganisms which thereby generate obnoxious odors. Since these microorganisms deplete the emulsifier in the fluid, the oil phase of the emulsion splits off resulting in an increased tramp oil level in the sump.
Biocides are commonly incorporated in metal working fluid formulations to control the growth of these microorganisms, but the biocides become depleted as the bath ages and the effect of the biocide declines so the microorganisms can eventually take over. These problems are particularly severe with soluble oil emulsion type metal working fluids, but they can also occur with synthetic types of fluids.
Attempts have been made to solve this problem. In U.S. Pat. No. 4,129,509 there is disclosed a sodium copper (II) citrate which is used as deodorizer and emulsion stabilizer for the soluble oil metal working fluids. In U.S. Pat. No. 4,055,655 this same material is used as a biocide. In both of these products the active ingredient provides a slow release of the copper ions which precipitate the hydrogen sulfide produced. Use of this material is restricted to soluble oil type fluids since these materials do not work with synthetic fluids.
3. Objects of the Invention
It is an object of this invention to formulate a powder composition which can be added to used metal working fluids to remove the obnoxious sulfurous odors that occur during plant shutdowns or when lower pH anaerobic conditions exist in the fluid as well as to recondition the used working fluid.
It is a further object of this invention to obtain a composition which eliminates rancid odors from the used metal working fluid and, when added in excess of that need to satisfy the demand of the existing malodors, will prevent their return.
It is a further object of this invention to obtain a composition which restores the milky white color to a used metal working fluid.
It is a further object of this invention to obtain a composition which increases the alkaline buffering capacity of a used metal working fluid and thus to reduce the rusting and/or corrosion of finished metal goods.
It is a further object of this invention to obtain a composition which increases the lubricity of a used metal working fluid.
It is another object of this invention to obtain a composition which when applied to a used metal working fluid lowers the microorganism count.
It is still another object of this invention to provide a composition which stabilizes the emulsion in a used metal working fluid to reduce the tramp oil content in the sump of the working fluid system.
It is still another object of this invention to provide a method whereby a used metal working fluid stays aerobic and its useful life is extended as well as improving the tool life and the appearance of the finished goods by adding a deodorant and a rejuvenate composition to the used metal working fluid.
These and further objects will become apparent as the description of the invention proceeds.